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nitrh tstrs getraut @Hita JOHN L. KRAUSER, OFk TYLERSBURG, PENNSYLVANIA, ASSIGNOR TO J. E. EMERSON, OF lRENTON, NEW JERSEY.

Letters Patent No. 71,625, dated December 3, 1867.

IMPROVEMENT IN saws.

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To ALL wHoM 1T MAY ooNeEnN:

Be it known that I, JOHN L. Knnusnn, of Tylersburg, in the county of Clarion, and 'State of Pennsylvania, have invented certain new and useful Improvements in Saws; and do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, and letters of reference marked thereon, similar letters referring to like lparts in all the figures, of whi`ch Figure 1 represents a side or face view of one of the saws.

Figure 2 represents a cross-section, taken throughv the dotted line b b in iig. 1.

Figure 3 represents `a perspective view of one of the teeth.

Figure d represents a cross-section, taken through the dotted lines c c of iig. 3.

v Figure represents a top view of one ofthe teeth,and also shows the thickness of the saw-blade.

Figure represents diierent methods of entering the teeth into the slots of the saw-blade.

l vFigure 7 represents a face or side view of one of the saws, with the teeth curved or circular instead of straight'. i

Figure 8l represents, in perspective, one of the blanks, or rather the shape of one of the blanks that are placed lin the rear of theteeth. l

Thenat'ure of this invention first consists in making the tongued and grooved saw-teeth thicker than the saw-plate, tovlessen .the amount of swaging and setting required to afford free passage of the saw-blade through 'the timber, as also to strengthen the teeth and `prevent their rapid reduction in ling and swaging.

The invention further consists in providing certain means for holding or resisting the teeth against their inward thrust. v

The invention further consists in providing the saw-plate and teeth with tongues and grooves, of peculiar form, when Vfitted suiiicient-ly tight,"to hold the teeth firmly in the saw-plate when in motion, without the aid of other fastenings.

Although the invention is applicable to all kinds of saws, I have adopted the circular saw tosillustrate my invention by.

` In fig. 1, a a a a represent saw-teeth or cutters, made thicker than the body or blade of the saw, and projecting equallyon both sides of the sawras shown at g. 5where H H shows the extrathickness of the teeth The slot S, gs. land 2, is provided with chamfered edges, as seen at D D, Ste., and it ismade slightly narrower at its outer extremity (A, g. 1) than at its base, so that when the Ytooth (which is made to iit snugly) is driven into the slot S, the gum B will act as a spring against the front part of the tooth, and thus eifectnally and firmly7 secure said tooth in the blade or body ofthe saw. The teeth a a a a, iig. 1, are made thicker than the body of the saw, to lessen the amount of swagmg or setting required to insure the free passage of the saw-blade through the timber. This extra thickness ofv the teeth also gives strength to them, and, from their thickness, are not reduced so rapidly in filing and swaging. The heel-point m, iig. 1) of the teeth is allowed to project a distance above the edge ofthe saw-plate, and when' this portion of the teeth is filed away they may be set out again, and a blank of suitable size placed behind them, as shown by c, in connection with the tooth a, fig. 1, to hold them out, and every time they are thus led off and set` out, a longer blank must be used,`and thus'two-thirds of the lengt-hof the tooth may be worn away by use before it need be replaced by a new one; By the Auseof the blanks behind the teeth, the latter are held firmly in their positions, and are prevented from beingdriven inward by the cutting action of the saw, or by the process of'swaging or spreading the points of the teeth.

Another method of holding the teeth firmly to the saw-plate, and in diii'erent positions, is shown at a', fig 1. In this plan a revolving rivet is inserted in the saw, as seen at K, tig. 1. rlhis rivet is attened on one side, as seen at T, and is furnished with a groove, L, to enable the operator, with a suitable instrument, to turn iti In the tooth a are notches P P P P, and by turning the attened part of the rivet K, so as to bring it on a line `with the under side of the tooth a', the latter is free to slide back and forth; but when it is desirable to hold the tooth in position, then the rivet is turned so that its round part will fit into one of the depressions P, which rmly holds it in that position.

In iig. 6 are shown severalrdifierent methods lof o r shapes for preparing the edges of the slots made the sew-plate, and in the edges of the teeth, a tongue and groove being preferable; the groove being made either -in the edge of the saw or in the tooth. I, however, prefer to make the groove in the tooth. The grooves may be made sufficiently smell'to gripe the tongue and hold the tooth rmly in the saw Without the nid of any other fastening, or they may be hammered or pressed down to make a, firmer connection or adhesion'of the parts, by

making the outer part ofthe groove smaller than the inner or bottom portion.

Having thus fully described the invention, what is claimed therein as new, and desired to be secured by Letters Patent,isi 1. Making the tongued und grooved teeth thicker than the sawwplate, as and for the purpose described.

2. The devices, or their substantial equivalents, for holding the teeth against their inward thrust, constructed substantially as deseribed. l

3. The tongues and grooves on and in the edges of the teethend saw-p1nt e, when thel grooves are made smaller than the tongues, by hommering,'p1'essing, or otherwise, so that the sides of the grooves form a. spring to clasp or V gripe the tongues suileiently tight to firmly hold the teeth in the sow when in motion, without the uid of any other fastening, substantially as described. Y i.

JOHN L. KRAUSER.

Witnesses;

JOHN ALT, QYRUs KRAUSER. 

